1. Field of the Invention
The present invention relates to an improved method for producing trifluoroethylene (hereinafter referred to as "TrFE") by reaction of 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafter referred to as "R-113") with hydrogen.
More particularly, the present invention relates to a method for producing TrFE by reaction of R-113 with hydrogen in the presence of a catalyst comprising palladium and at least one selected from gold, tellurium, antimony, bismuth, and arsenic.
2. Description of the Related Art
Trifluoroethylene is a useful compound as a monomer for functional fluorine-containing polymers and as an intermediate material for biologically active compounds.
A known method for producing TrFE is a reaction of chlorotrifluoroethylene (hereinafter referred to as "CTFE") with hydrogen in the presence of palladium or platinum supported by an active carbon carrier or an alumina carrier (Japanese Patent Publication No. Sho 46-2324, Japanese Patent Application Laid-Open No. Sho 62-252736, and U.S. Pat. No. 2,802,887).
This method, which uses CTFE as a starting material, requires production of CTFE, for example by dechlorination of R-113 with zinc.
Accordingly, this method of TrFE production requires naturally two steps of reactions passing through CTFE as an intermediate, which is disadvantageous industrially.
Another method is disclosed in which TrFE is produced in one step of gas-phase reaction of R-113 with hydrogen in the presence of palladium catalyst supported by active carbon (Japanese Patent Publication Sho 43-8454).
This method is highly advantageous for industrial production of TrFE since the TrFE is produced from R-113 and hydrogen through a direct one-step reaction.
This method, however, is still unsatisfactory for industrial production of TrFE because of low catalyst activity and the short life thereof.
After comprehensive investigation to solve the above-mentioned disadvantages, the inventors of the present invention found a highly active and long-lived catalyst for production of TrFE from R-113 and hydrogen, and have accomplished the present invention.